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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

High-throughput evaluation of protein folding conditions and expression constructs for structural genomics / High-throughput evaluation of protein folding conditions and expression constructs for structural genomics

Scheich, Christoph January 2004 (has links)
Das E. coli Expressionssystem ist das am häufigsten angewandte hinsichtlich der rekombinante Proteinexpression für strukturelle und funktionelle Analysen aufgrund der hohen erzielten Ausbeuten und der einfachen Handhabbarkeit. Allerdings ist insbesondere die Expression eukaryotischer Proteine in E. coli problematisch, z.B. wenn das Protein nicht korrekt gefaltet ist und in unlöslichen Inclusion Bodies anfällt. In manchen Fällen ist die Analyse von Deletionskonstrukten oder einzelnen Proteindomänen der Untersuchung des Vollängeproteins vorzuziehen. Dies umfasst die Herstellung eines Satzes von Expressionskonstrukten, welche charakterisiert werden müssen. In dieser Arbeit werden Methoden optimiert und evaluiert für die in vitro-Faltung von Inclusion Body-Proteinen sowie die Entwicklung einer Hochdurchsatz-Charakterisierung von Expressionskonstrukten. Die Überführung von Inclusion Body-Proteinen in den nativen Zustand beinhaltet zwei Schritte: (a) Auflösen mit einen chaotropen Reagenz oder starkem ionischen Detergenz und (b) Faltung des Proteins durch Beseitigung des Chaotrops begleitet von dem Transfer in einen geeigneten Puffer. Die Ausbeute an nativ gefaltetem Protein ist oft stark eingeschränkt aufgrund von Aggregation und Fehlfaltung; sie kann allerdings durch die Zugabe bestimmter Additive zum Faltungspuffer erhöht werden. Solche Additive müssen empirisch identifiziert werden. In dieser Arbeit wurde eine Testprozedur für Faltungsbedingungen entwickelt. Zur Reduzierung der möglichen Kombinationen der getesteten Additive wurden sowohl empirische Beobachtungen aus der Literatur als auch bekannte Eigenschaften der Additive berücksichtigt. Zur Verminderung der eingesetzten Proteinmenge und des Arbeitsaufwandes wurde der Test automatisiert und miniaturisiert mittels eines Pipettierroboters. 20 Bedingungen zum schnellen Verdünnen von denaturierten Proteinen werden hierbei getestet und zwei Bedingungen zur Faltung von Proteinen mit dem Detergenz/Cyclodextrin Protein-Faltungssystem von Rozema et al. (1996). 100 µg Protein werden pro Bedingung eingesetzt. Zusätzlich werden acht Bedingungen für die Faltung von His-Tag-Fusionsproteinen (ca. 200 µg), welche an eine Metallchelat-Matrix immobilisiert sind, getestet. Die Testprozedur wurde erfolgreich angewendet zur Faltung eines humanen Proteins, der p22 Untereinheit von Dynactin, welche in E. coli in Inclusion Bodies exprimiert wird. So wie es sich bei vielen Proteinen darstellt, war auch für p22 Dynactin kein biologischer Nachweistest vorhanden, um den Erfolg des Faltungsexperimentes zu messen. Die Löslichkeit des Proteins kann nicht als eindeutiges Kriterium dienen, da neben nativ gefaltetem Protein, lösliche fehlgefaltete Spezies und Mikroaggregate auftreten können. Diese Arbeit evaluiert Methoden zur Detektion kleiner Mengen nativen Proteins nach dem automatisierten Faltungstest. Bevor p22 Dynactin gefaltet wurde, wurden zwei Modellenzyme zur Evaluierung eingesetzt, bovine Carboanhydrase II (CAB) und Malat Dehydrogenase aus Schweineherz-Mitochondrien. Die wiedererlangte Aktivität nach der Rückfaltung wurde korreliert mit verschiedenen biophysikalischen Methoden. Bindungsstudien mit 8-Anilino-1-Naphtalenesulfonsäure ergaben keine brauchbaren Informationen bei der Rückfaltung von CAB aufgrund der zu geringen Sensitivität und da fehlgefaltete Proteine nicht eindeutig von nativem Protein unterschieden werden konnten. Tryptophan Fluoreszenzspektren der rückgefalteten CAB wurden zur Einschätzung des Erfolges der Rückfaltung angewandt. Die Verschiebung des Intensitätsmaximum zu einer niedrigeren Wellenlänge im Vergleich zum denaturiert entfalteten Protein sowie die Fluoreszenzintensität korrelierten mit der wiedererlangten enzymatischen Aktivität. Für beide Modellenzyme war analytische hydrophobe Interaktionschromatographie (HIC) brauchbar zur Identifizierung rückgefalteter Proben mit aktivem Enzym. Kompakt gefaltetes, aktives Enzym eluierte in einem distinkten Peak im abnehmenden Ammoniumsulfat-Gradienten. Das Detektionslimit für analytische HIC lag bei 5 µg. Im Falle von CAB konnte gezeigt werden, dass Tryptophan-Fluoreszenz-Spektroskopie und analytische HIC in Kombination geeignet sind um Falsch-Positive oder Falsch-Negative, welche mit einem der Monitore erhalten wurden, auszuschließen. Diese beiden Methoden waren ebenfalls geeignet zur Identifizierung der Faltungsbedingungen von p22 Dynactin. Tryptophan-Fluoreszenz-Spektroskopie kann jedoch zu Falsch-Positiven führen, da in machen Fällen Spektren von löslichen Mikroaggregaten kaum unterscheidbar sind von Spektren des nativ gefalteten Proteins. Dies zusammenfassend wurde eine schnelle und zuverlässige Testprozedur entwickelt, um Inclusion Body-Proteine einer strukturellen und funktionellen Analyse zugänglich zu machen. In einem separaten Projekt wurden 88 verschiedene E. coli-Expressionskonstrukte für 17 humane Proteindomänen, welche durch Sequenzanalyse identifiziert wurden, mit einer Hochdurchsatzreinigung und –faltungsanalytik untersucht, um für die Strukturanalyse geeignete Kandidaten zu erhalten. Nach Expression in einem Milliliter im 96er Mikrotiterplattenformat und automatisierter Proteinreinigung wurden löslich exprimierte Proteindomänen direkt analysiert mittels 1D ¹H-NMR Spektroskopie. Hierbei zeigte sich, dass insbesondere isolierte Methylgruppen-Signale unter 0.5 ppm sensitive und zuverlässige Sonden sind für gefaltetes Protein. Zusätzlich zeigte sich, dass – ähnlich zur Evaluierung des Faltungstests – analytische HIC effizient eingesetzt werden kann zur Identifizierung von Konstrukten, welche kompakt gefaltetes Protein ergeben. Sechs Konstrukte, welche zwei Domänen repräsentieren, konnten schnell als tauglich für die Strukturanalyse gefunden werden. Die Struktur einer dieser Domänen wurde kürzlich von Mitarbeitern gelöst, die andere Struktur wurde im Laufe dieses Projektes von einer anderen Gruppe veröffentlicht. / For recombinant production of proteins for structural and functional analyses, the E. coli expression system is the most widely used due to high yields and straightforward processing. However, particularly the expression of eukaryotic proteins in E. coli is often problematic, e.g. when the protein is not folded correctly and is deposited in insoluble inclusion bodies. In some cases it is favourable to analyse deletion constructs of a protein or an individual protein domain instead of the full-length protein. This implies the generation of a set of expression constructs that need to be characterised. In this work methods to optimise and evaluate in vitro folding of inclusion body proteins as well as high-throughput characterisation of expression constructs were developed. Transferring inclusion body proteins to their native state involves two steps: (a) solubilisation with a chaotropic reagent or a strong ionic detergent and (b) folding of the protein by removal of the chaotrop accompanied by the transfer into an appropriate buffer. The yield of natively folded protein is often substantially reduced due to aggregation or misfolding; it may, however, be improved by certain additives to the folding buffer. These additives need to be identified empirically. In this thesis a screening procedure for folding conditions was developed. To reduce the number of possible combinations of screening additives, empirical observations documented in the literature as well as well known properties of certain screening additives were considered. To decrease the amount of protein and work invested, the screen was miniaturised and automated using a pipetting robot. Twenty rapid dilution conditions for the denatured protein are tested and two conditions for folding of proteins using the detergent/cyclodextrin protein folding system of Rozema et al. (1996). 100 µg protein is used per condition. In addition, eight conditions can be tested for folding of His-tagged proteins (approx. 200 µg) immobilised on metal chelate resins. The screen was successfully applied to fold a human protein, the p22 subunit of dynactin that is expressed in inclusion bodies in E. coli. For p22 dynactin – as is the case for many proteins – there was no biological assay available to assess the success of the folding screen. Protein solubility can not be used as a stringent criterion because beside natively folded protein, soluble misfolded species and microaggregates may occur. This work evaluates methods to detect small amounts of natively folded protein after automated folding screening. Before folding screening with p22 dynactin, two model enzymes, bovine carbonic anhydrase II (CAB) and pig heart mitochondrial malate dehydrogenase, were used for evaluation. Recovered activity after refolding was correlated to different biophysical methods. 8-anilino-1-naphtalenesulfonic acid binding-experiments gave no useful information when refolding CAB, due to low sensitivity and because misfolded protein could not be readily distinguished from native protein. Tryptophan fluorescence spectra of refolded CAB were used to assess the success of refolding. The shift of the intensity maximum to a shorter wavelength, compared to the denaturant unfolded protein, as well as the fluorescence intensity correlated to recovered enzymatic activity. For both model enzymes, analytical hydrophobic interaction chromatography (HIC) was useful to identify refolded samples that contain active enzyme. Compactly folded, active enzyme eluted in a distinct peak in a decreasing ammonium sulfate gradient. The detection limit of analytical HIC was approx. 5 µg. In case of CAB, tryptophan fluorescence spectroscopy and analytical HIC showed that both methods in combination can be useful to rule out false positives or false negatives obtained with one method. These two methods were also useful to identify conditions for folding of p22 dynactin. However, tryptophan fluorescence spectroscopy can lead to false positives because in some cases spectra of soluble microaggregates are not well distinguishable from spectra of natively folded protein. In summary, a fast and reliable screening procedure was developed to make inclusion body proteins accessible to structural or functional analyses. In a separate project, 88 different E. coli expression constructs for 17 human protein domains that had been identified by sequence analysis were analysed using high-throughput purification and folding analysis in order to obtain candidates suitable for structural analysis. After 96 deep-well microplate expression and automated protein purification, solubly expressed protein domains were directly analysed using 1D ¹H-NMR spectroscopy. It was found that isolated methyl group signals below 0.5 ppm are particularly sensitive and reliable probes for folded protein. In addition – similar to the evaluation of a folding screen – analytical HIC proved to be an efficient tool for identifying constructs that yield compactly folded protein. Both methods, 1D ¹H-NMR spectroscopy and analytical HIC, provided complementary results. Six constructs, representing two domains, could be quickly identified as targets that are well suitable for structural analysis. The structure of one of these domains was solved recently by co-workers, the other structure was published by another group during this project.
312

In-Vehicle Screen Density : Driver distraction and User Preferences for Low vs High Screen Densisty

Johansson, Hanna, Walter, Katarina January 2005 (has links)
Many information technology artefacts can be found in today’s cars. The interaction with these artefacts is the driver’s secondary task while driving the car in a safe way is the primary task. When designing interfaces for in-vehicle usage, measures have to be taken in order to make the interaction with the artefact suit the in-vehicle environment. One of these measures is to have the appropriate screen density level, which is the amount of information present on the screen. This thesis compares the usability of two integrated in-vehicle display prototypes, one with low screen density and one with high screen density. The usability comparison considers both safety and user preferences. Safety was measured by a Lane Change Test (LCT) which measures distraction of a primary task while performing a secondary task, and user preferences was measured with a questionnaire. Before the comparison was made, controls and a graphical user interface were designed. Results showed no significant difference in driver distraction between performing tasks on the high screen density display and the low screen density display. However, a vast majority of the users preferred high screen density over low. Furthermore, the distraction levels for both the high and the low screen density displays were below the proposed 0.5 meter limit for allowed driver distraction. The results indicate that in-vehicle displays can have a high level of screen density without imposing a level of distraction on the driver that is unsuitable for driving.
313

Future Upgrades of the LHC Beam Screen Cooling System

Backman, Björn January 2006 (has links)
The topic of this thesis concerns the LHC, the next large particle accelerator at CERN which will start operating in 2007. Being based on superconductivity, the LHC needs to operate at very low temperatures, which makes great demands on the cryogenic system of the accelerator. To cope with the heat loads induced by the particle beam, a beam screen cooled with forced flow of supercritical helium is used. There is an interest in upgrading the energy and luminosity of the LHC in the future and this would require a higher heat load to be extracted by the beam screen cooling system. The objective of this thesis is to quantify different ways to upgrade this system by mainly studying the effects of different pressure and temperatures levels as well as a different cooling medium, neon. For this a numerical program which simulates one-dimensional pipe flow was constructed. The frictional forces were accounted for by the empirical concept of friction factor. For the fluid properties, software using empirically made correlations was used. To validate the numerical program, a comparison with previous experimental work was done. The agreement with experimental data was good for certain flow configurations, worse for others. From this it was concluded that further comparisons with experimental data must be made in order to tell the accuracy of the mathematical model and the correlations for fluid properties used. When using supercritical helium, thermo-hydraulic instabilities may arise in the cooling loop. It was of special interest to see how well a numerical program could simulate and predict this phenomenon. It was found that the numerical program did not function for such unstable conditions; in fact it was much more sensitive than what reality is. For the beam screen cooling system we conclude that to cope with the increased heat loads of future upgrades, an increase in pressure level is needed regardless if the coolant remains helium, or is changed to neon. Increasing the pressure level also makes that the problems with thermo-hydraulic instabilities can be avoided. Of the two coolants, helium gave the best heat extraction capacity. Unlike neon, it is also possible to keep the present temperature level when using helium.
314

"Surfnacke"- ett växande hälsoproblem bland ungdomar? : Skärmbaserade aktiviteter, fysisk inaktivitet, muskuloskeletala symptom och smärtintensitet

Selinder, Marita January 2013 (has links)
The aim of this study was to analyse ninth graders self reported screen based activities, sedentary time and musculoskeletal symptoms and pain intensity. The other aim was to examine changes regarding musculoskeletal pain and inactivity between ninth graders from a cross sectional study in year 2004. To meet this aim, following questions were designed: How is the relationship between screen based activities, inactivity, musculoskeletal symptoms, pain intensity and differences between girls and boys? How have musculoskeletal symptoms and screen time changed since year 2004? Method: The method used for this study was a quantitative method. The research was carried out using a questionnaire that was answered by pupils from 11 schools from all over Sweden. The response rate was 85 % (n=465). The level of statistical significance was set at p<0.05. Results: Mobile phones were used three times more by girls and TV Games were used seven times more by the boys.  Tablet computers were used more randomly by 80% of the youths. Headache occurred 58% and neck pain occurred 68 % with those who used mobile phone >3 and >5 hours per day. Backache occurred with 19% of those watching TV > 3 hrs. Headache ongoing for more than a month occurred twice as much among the girls and was perceived as having a severe effect on everyday life. Boys reported neck ache and shoulder ache longer than a month somewhat to a greater extent. Nearly twice as many of the boys considered themselves being more physical active and resemble the most active person. Total sedentary time was not significant but a third of the youths reported that sitting time for 7-9 hrs during weekdays and 4-6 hrs during weekends. Differences between 2004 and 2013 showed that occurrence of ache and continuous back pain decreased whilst headache and continuous back pain increased with the boys. Conclusions: Headaches, neck pain and backaches are common among 9th graders and it seems to be a relationship with time exposure to different screen activities. Further research investigating gender differences and pain is important, in particular among girls who seem to be more vulnerable. / Studiens syfte var att analysera niondeklassares självrapporterade skärmbaserade aktiviteter, fysisk inaktivitet samt muskuloskeletala symptom, smärtintensitet och påverkan i vardagen. Vidare var syftet att göra jämförelser med resultat från en tvärsnittsstudie år 2004 i samma skolor för att se eventuella skillnader. Frågeställningarna var: Hur ser sambandet ut med skärmbaserade aktiviteter, fysisk inaktivitet samt muskuloskeletala symtom, smärtintensitet och påverkan i vardagen? Finns några könsskillnader? Hur har muskuloskeletala besvär, inaktivitet och skärmbaserad tid förändrats i jämförelse med niondeklassare år 2004? Metod: En kvantitativ tvärsnittsstudie med enkäter som besvarades av 465 elever (85 %) på 11 skolor. Populationen hämtades från SIH projektet år 2004 som bestod av ett slumpmässigt urval från skolor i hela Sverige. Resultat: Mobiltelefonen användes av tre gånger så många flickor, TV spel av sju gånger så många pojkar. Surfplatta användes aldrig eller sällan av 80 %. Nackvärk och huvudvärk förekom ofta bland 68 % respektive 58 % av de som använde mobilen >3 timmar eller mer. Ryggvärk förekom bland 19 % som tittade TV > 3 timmar. Huvudvärk mer än en månad förekom dubbelt så ofta hos flickor och upplevdes ha en svår påverkan i vardagen. Dubbelt så många pojkar ansåg sig mest fysiskt aktiva i vardagen och ansåg sig likna den person som är mest fysiskt aktiv. Stillasittande tid var inte signifikant men en tredjedel av ungdomarna uppgav att de sitter stilla 7-9 h på vardag och 4-6 h på helgdag. Mellan år 2004 och år 2013 ökade förekomsten av huvudvärk och pågående ryggsmärta bland pojkar. Slutsats: Smärta i huvud, nacke och rygg är ofta förekommande bland niondeklassare och samband tycks finnas med långvarig exponering av olika skärmbaserade aktiviteter Självrapporterad smärta har i jämförelse med en tvärsnittsstudie år 2004 minskat förutom huvudvärk och ryggsmärta som ökat bland pojkar. Vidare forskning kring könsskillnader och smärta är angeläget i synnerhet bland flickor som är mer drabbade.
315

The initial development and content validity of an Asperger's Syndrome self-screening instrument for adults

Fung, Karen 25 February 2011
This research addresses the lack of an existing psychometrically sound Aspergers Syndrome self-screening instrument for adults. Initial instrument development procedures were carried out by creating an item pool using existing Asperger measures. Items were rewritten following common item writing rules suggested by several researchers as reference. Five new domains were created and the items were re-categorized. Expert panel of nine judges specialized in Psychometrics, ASD, School Psychology, and Speech-Language Pathology were asked to rate the relevancy of items to their domains in order to obtain evidence of content validity. These experts were chosen because of their relatedness to Aspergers Syndrome and their expertise in instrument development. First, the quality of the judges ratings were examined to identify any aberrant judges. Ratings were then analyzed using the remaining six judges using three descriptive and three quantitative methods to examine the representativeness and relevancy of each item to their domain. A total of 55 items were identified as satisfactory by the judges. The second part of this study was to compare the content validity analytical methods. It was concluded that the percentage agreement, the content validity index (CVI), and the content validity coefficients (VIK) were the best methods to use in selecting the satisfactory items. This research aims to bring more attention to the importance of psychometric properties in measures for the Autism Spectrum Disorder field. It also hope to shed some light on which content validity analyses would best be used under certain circumstances. Limitations of study and future directions were also discussed.
316

Screening of natural products and Alkylating agents for Antineoplastic Activity

Kanyanda, Stonard Sofiel Elisa January 2007 (has links)
<p>Background and objectives: Apoptosis is a process in which a cell programmes its own death. It is a highly organized physiological mechanism in which injured or damaged cells are destroyed. Apart from physiological stimuli however, exogenous factors can induce apoptosis. Many anti-cancer drugs work by activating apoptosis in cancer cells. Natural substances have been found to have the ability to induce apoptosis in various tumour cells and these substances have been used as templates for the construction of&nbsp / novel lead compounds in anticancer treatment. On the other hand, alkylating agents such as cisplatin, cis- [PtCl2 (NH3) 2] have been widely used as antineoplastic agents for a&nbsp / wide variety of cancers including testicular, ovarian, neck and head cancers, amongst others. However, the use of cisplatin as an anticancer agent is limited due to toxicity and resistance problems. The aim of this present study was to screen the leaves of Rhus laevigata, a South African indigenous plant, for the presence of pro-apoptotic and&nbsp / anti-proliferative natural compounds and also to screen newly synthesised palladium based complexes (15 and 57) and a platinum based complex (58) for their antineoplastic&nbsp / activities tested against a panel of cell lines. Results. The results showed that crude methanol extracts from Rhus laevigata as well as the newly synthesised palladium based complexes (15 and 57) and a platinum based complex (58) induced apoptosis in the cell lines tested, as demonstrated by the externalization of phosphatidylserine, mitochondrial membrane permeabilization,caspase-3 activation, and DNA fragmentation. Caski (cervical cancer) and H157 (non small cell lung carcinoma) cell lines treated with the methanol extract from Rhus laevigata however, were more resistant to apoptosis induction. Among the metallocomplexes, complexes 15 and 57, palladium based complexes, were the most active. Conclusion: The methanol extract from the leaves of Rhus laevigata contain pro-apoptotic and antiproliferative natural compound(s), which need to be characterised and elucidated as they could provide the much-needed lead compounds in the fight against cancer. On the other hand the newly synthesized palladium complexes also need further evaluation to&nbsp / see if they can be used as anticancer agents that can overcome the problems associated with cisplatin.</p>
317

La escultura de Cristina Iglesias. Dar cuerpo a lo imaginario

Hidalgo García, Miguel Ángel 13 January 2009 (has links)
La presente tesis doctoral se organiza en dos apartados: 1) un estudio formal de sus esculturas 2) su concepción de lo artístico. Su formación como escultora cabalga entre la recuperación del objeto y la imagen por parte de la Nueva Escultura Inglesa y el interés centroeuropeo por una escultura-arquitectónica que es "espacio poético".Iglesias investiga sobre hasta dónde podemos emplear los materiales. En cuanto a las formas, ha levantado durante toda su carrera muros-pantalla que construyen espacios. Si hay un significado general a todas las piezas es la idea de imaginar que el lugar que se mira o nos cobija, es real.Primero ver, luego imaginar. Así podría resumirse la intención de Iglesias con sus construcciones. Sus esculturas son espacios reales y representaciones al mismo tiempo. La escultura de Iglesias es un "espacio de percepciones", representaciones simbólicas de amenaza, cobijo, miedo, deseo, opresión, desorientación...como estar en un laberinto. / The present doctoral thesis is organized in two parts: 1) a formal study o her sculptures 2) the conception of Cristina Iglesias about the artistics.Her training like a sculptor was between the recovery of space and the image by the New English Sculpture and the interest Centro European by an architectural sculpture that is "poetic space".Cristina Iglesias researches on until where we can employ the materials. Regarding the forms, she has put on during her career screen- walls that build space.If there is a general meaning to all pieces is the idea to imagine that the place that look or receive us, is real.First see, afterwards imagine. Her sculptures are real spaces and representations to the same time. Iglesias´s sculpture is a "space of perceptions", symbolic representations of threat, shelter, fear, wish, oppressions, disorientation. Like being in a labyrinth
318

Is a big button interfaceenough for elderly users? : Towards user interface guidelines for elderly users

Phiriyapokanon, Tanid January 2011 (has links)
In the world today, the portion of aging people grows continuously. Due to successfulof healthcare services, people are living longer and the number of newborn isdecreasing. This can imply that the population of young and working people isdecreasing in many countries. This leads to the mean value incrementing of the meanworld population’s age value in the whole world. It has become more and moreimportant to consideration human factors of elderly people in many businesses.Software companies have to consider design of software concerning of usability forageing people. Currently, most of the software is designed to support younger users.To support elderly users, we have to consider more on age-related differences. Thisthesis presents a literature survey, and related theories used in designing graphic userinterface for ageing people. Besides, criteria for designing software for older users arealso discussed and suggested as guidelines for future studies and development. Thepurpose is to improve older users’ potential in using information technologies, and topotentially allow older users to gain more benefit from using of computer software.A case study for software design for elderly users was implemented to verifysuggested guideline and gain deeper design understanding. The elderly volunteerswere involved in design evaluation process. The results from case study have showneffectiveness of the design guideline approach.
319

Flexible touch screen for Rear Seat Entertainment

Öhman, Tanja January 2011 (has links)
Rapporten beskriver förslag på framtidens ”Rear Seat Entertainment” som baseras på användning av pekskärm, istället för de DVD-baserade TV-skärmar som finns i t ex Volvo S80 i dagsläget. Projektet utfördes som ett examensarbete inom integrerad produktutveckling vid Högskolan i Skövde. Syftet med arbetet var att hitta lösningar som möjliggör användning av ”touchteknik” som kräver armavstånd till displayen. Arbetet delades upp i tre delar där val av pekskärmsenhet (inbyggd eller mobil), positionering av pekskärmen i bilen enligt ergonomiska rekommendationer, samt anpassning för olika stora personer inkluderade barn och utformning av infästningselement har utvecklats.  Arbete inleddes med litteraturstudier om interaktion av pekbaserade interface, målgruppsundersökningar, sammanställning av marknadsundersökningar, trendanalyser samt ergonomiska förutsättningar och miljöutvärderingar.  För idégenereringen användes kreativa och systematiserade metoder. Urval av idéer skedde i samråd med Volvo och med hjälp av en konceptvalsmatris. Det  slutliga  konceptet  baseras  på  användningen  av  mobila  pekskärmsenheter.  Dessa  motsvarar  bäst  de  i dagsläget ställda kriterierna på användning, ekonomi, miljö och flexibilitet. Dessutom erhålls en enklare mjuk- och hårdvaruuppdatering.   Positionering  av  pekskärmar  i  bilens  baksäte  gjordes  med  hjälp  av  ergonomiska  rekommendationer  samt databaserade beräkningar och simuleringar.    Utformning av infästningselementen anpassades till kravspecifikationen och resulterade i ett fäste som håller fast enheten med hjälp av  permanentmagneter  som byggs in i  ett infästningselement  på stolens baksida och ett i fodralet för surfplattan. Arbetet har lett till skärmar som enkelt kan fästas med magnetkrafter.
320

Inkjet and Screen Printed Electrochemical Organic Electronics

Mannerbro, Richard, Ranlöf, Martin January 2007 (has links)
Linköpings Universitet och Acreo AB i Norrköping bedriver ett forskningssamarbete rörande organisk elektrokemisk elektronik och det man kallar papperselektronik. Målet på Acreo är att kunna trycka denna typ av elektronik med snabba trycktekniker så som offset- eller flexotryck. Idag görs de flesta demonstratorer och prototyper, baserade på denna typ av elektrokemisk elektronik, med manuella och subtraktiva mönstringsmetoder. Det skulle vara intressant att hitta fler verktyg och automatiserade tekniker som kan underlätta detta arbete. Målet med detta examensarbete har varit att utvärdera vilken potential bläckstråleteknik respektive screentryck har som tillverkningsmetoder för organiska elektrokemiska elektroniksystem samt att jämföra de båda teknikernas för- och nackdelar. Vad gäller bläckstråletekniken, så ingick även i uppgiften att modifiera en bläckstråleskrivare avsedd för kontor/hemmabruk för att möjliggöra tryckning av de två grundläggande materialen inom organisk elektrokemisk elektronik - den konjugerade polymeren PEDOT och en elektrolyt. I denna uppsats rapporteras om hur en procedur för produktion av elektrokemisk elektronik har utvecklats. Världens första elektrokemiska transistor som producerats helt med bläckstråleteknik presenteras tillsammans med fullt fungerande implementeringar i logiska kretsar. Karaktärisering av filmer, komponenter och kretsar som producerats med bläckstråle- och screentrycksteknik har legat till grund för den utvärdering och jämförelse som har gjorts av teknikerna. Resultaten ser lovande ut och kan motivera vidare utveckling av bläckstrålesystem för produktion av prototyper och mindre serier. En kombination av de båda nämnda teknikerna är också ett tänkbart alternativ för småskalig tillverkning. / Linköping University and the research institute Acreo AB in Norrköping are in collaboration conducting research on organic electrochemical electronic devices. Acreo is pushing the development of high-speed reel-to-reel printing of this type of electronics. Today, most demonstrators and prototypes are made using manual, subtractive patterning methods. More tools, simplifying this work, are of interest. The purpose of this thesis work was to evaluate the potential of both inkjet and screen printing as manufacturing tools of electrochemical devices and to conduct a comparative study of these two additive patterning technologies. The work on inkjet printing included the modification of a commercially available desktop inkjet printer in order to print the conjugated polymer PEDOT and an electrolyte solution - these are the two basic components of organic electrochemical devices. For screen printing, existing equipment at Acreo AB was employed for device production. In this report the successful development of a simple system and procedure for the inkjet printing of organic electrochemical devices is described. The first all-inkjet printed electrochemical transistor (ECT) and fully functional implementations of these ECTs in printed electrochemical logical circuits are presented. The characterization of inkjet and screen printed devices has, along with an evaluation of how suitable the two printing procedures are for prototype production, been the foundation of the comparison of the two printing technologies. The results are promising and should encourage further effort to develop a more complete and easily controlled inkjet system for this application. At this stage of development, a combination of the two technologies seems like an efficient approach.

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